Active participation in the multiinstitutional cooperative studies of the NSABP under the leadership of Dr. Bernard Fisher will be continued. Also, patients will be entered into any future protocols that may be set up for Stages I and III breast cancer. The following are other projects being conducted at our institution: a) Immunologic studies on regional lymph nodes are being performed and will be continued in cooperation with the McGill Cancer Centre. b) A cooperative study of the chemotoxis of lymphocytes to autologous breast cancer cells has been set up with Dr. Peter Noble (McGill University). c) another study to determine the leval of the thiol proteinase cathepsin B from the serum and removed specimens of patients with breast cancer is underway with Dr. A.R. Poole (Shriner Hospital). d) A joint project to study by radioimmunoassay the levels of catechol estrogens in the plasma and urine of patients with breast cancer has been initiated with Dr. S. Franke (Department of Obs/Gyn. Research, Royal Victoria Hospital).